Originally shielding was provided using RF tape. Thereafter housings made from a tinned steel sheet by bending and by soldering the corners were used. The housings were usually affixed to the circuit board manually, normally by manual soldering, the components being accessed by removing or opening the shielding housing.
Opening the shielding housings for inspection and tuning is no longer necessary due to the quality of the state of the art components. Tuning is also achieved by some method other than by turning screws beneath the cover, for example through software or in some other more economical manner.
The most significant characteristics of a housing are ease of assembly and minimum space consumption so that the components of an electronic device may be shielded in an assembly which is easy to manufacture and which may be located within as small a device as possible.